Coin controlled oscillator for relay operation



April 29, 1952 A. M. GoRDoN 2,594,424

COIN CONTROLLED OSCILLATOR FOR RELAY OPERATION Filed July 2l, 1949 RamssHow |N 4`fENERG|zEo PoslTloN (D @D l* i yg2 .u i INVENTOR. i /exa/zc/erM @orc/azz l A TTQRNEYS.

Patented Apr. 29, 1952 COIN CONTROLLED OSCILLATOR FOR RELAY OPERATIONAlexander M. Gordon, Providence, R. I., assignor tu Max. L. Grant,Providence, R. I.

Application July 21, 1949,y Serial No. 106,075

3l Claims. (Cl. 1'75-320) This invention relates to anA electric circuitfor controlling a fare registering machine, particularly a machine ofthe type shown in my co-pending application,l Serial No. 83,066, filedlMarch 23, 1949.

The electric circuit shown in the above application employs a photocellAfor: providing the electrical signal of a predeterminedl and constantiixed value according to the diameter of the coin passed between thephotocell andits'exciter lamp.

A general object ofj this invention isv the provision of an electriccircuit in which the electrical signal will be provided in accordancetothe mass and composition of the particular coin to be registered.

A more specific object of this invention is the provision of an electriccircuit operable tov provide an electrical signal'n of a predeterminedand constant fixed value in accordance to the mass and composition of'acoin passed' through the magnetic field of an oscillator coil and toincrease the strength of thesignalby an amplier tube to operate relaysto; actuate; the solenoid ci a counter for'registering a particularcoin.

WithY these and' other objects in view,V thel invention consists ofcertain novellfeatures as will be more fully described and particularly`pointed out in the" appended' claims.

In the accompanyingdrawings:

Figure lis an electricalfcircuit embodying my invention;

Figure 2 is a plan View of a coil assembly; and

Figure 3 is a perspective view of a coil assembly in position on oneside of the coin-receivingpanel, showing a coin in registerlaxially'with the coil assembly shown in Figure 2.

Referring to Figure 1, I and II indicate two identical oscillatorcir-cuits whichY areV tuned to the same frequency range andV operatefrom a source of conventional full wavevacuum` tube rectifier powersupply IZ'Operatingfrom-an'A. C. power source. The: circuits` may be of:a conventional design providinggridand'anode windings I3 and I4 intheoscillator'circuit IU and similar grid and anode windings I5 and IS'inthe oscillator circuit II. The grid winding I3 is connected in serieswith a self-bias networkf'I1 to the grid of the oscillator tube I8 andtothe cathode of said tube I8. ThefgridwindingIS is similarly connectedinseries with asimilar self-'bias network I9 to the grid oftheoscillator'tube- 20 and to the cathode ofthesaid` tube 20. Thecathode of both oscillator-tubes are connected to; the. negativeterminal 2I .of the powersupplyI 2. Oneiside of theanodeA winding.j I4is1ccnnected to the anode of oscillator tube. I8 and its other side tothe positivel terminal 22 or" the power supply I2. Tuning capacitor 23and padding capacitor 24 are connected in parallel across' the anodewinding I4 and similar capacitorsv 25 and 2B are similarly connectedacross the anode. winding I6 of oscillator II resulting in identicalconnection for the oscillator tubes I8 and 2D. The operation of theoscillator circuits in that they produce electrical oscillations atagiven frequency is conventional.

The two circuits I and I I are coupled by'means of a link circuit 21having a winding 28 inductively coupled to the grid and anode windingsI3 and I4 of circuitv I0 and a similar winding 29 inductively coupled tothe grid and. anode wind'- ings I 5 and I 6 of oscillator circuit I I.The windings 28 and 23 are wound oppositely' to the said grid and anodewindings and areY connected in series to the plate of a diode rectifiertube 30 and in series with a diode resistor 3| to therv cathode ofthesaid tube 30. The windingsv I3, I4, and: I5 are assembled side byside on a non-metallic core to provide a coil assembly 32 (see Fig. 2).The windings I5, I6, and 29 a'resimilarly assembled to provide alsimilar coil assembly (not shown). These two coils are separatedlsufficiently or shielded one from the other` so` as to prevent aninductive coupling betweenv the said oscillator circuits. Since the linkcircuit 21 is tightly coupled to both oscillator tank circuits 33 and34', the twov oscillator circuits will maintain identical frequencies.

Thev coil assembly 32 is positioned on one side of a non-metallic panel355 (see Fig. 3) havinga coin-receiving recess 36 on the opposite'sidethereof in which an abutment in the form of spaced pins 31 which areslidably mounted to be moved in and out of the path cf travel of thecoin to be registered and mechanically linked (not shown) to be solenoidoperated. The pins are positioned to hold the said coin in: the recessat a location approximately axially with the said coil 32. Thepresenceof a coin in the magnetic field of the coil 32 changesy the coilinductance', frequency is directly'proportional t`o in'ductance,therefore the frequency of` oscillator circuit I0 is also changed. Itshould be noted that the coil inductance will be changed by eitherthema-ss (size) of the coin, or by thecomposition' ofthe coin or by acombination ofv both. Hence there is a definite value of inductance ofthe coil 32 for every size and composition of coin positioned over saidcoil 32.

This.z change lin inductanceV of? coil 32 causes a change in thefrequency of the oscillator circuit II), as above mentioned, and thegreater the change in inductance the greater the change in frequency.The oscillator II, which is linked to the oscillator Ill through thelink circuit 21, will prevent this frequency shift by transferring thenecessary reactive component of current through the link circuit 21 tocompensate for the reactive (inductive reactance) change in theoscillator I8 caused by the presence of the coin in position over thecoil 32. The changes in transferred current is practically linear withchanges in inductance as produced by the coin in the vfield of the coil32. This alternating link current flowing in the link circuit 21 isconverted to a direct current by the diode rectifier tube 35 andproduces a direct current voltage across the resistor 3 I. This signalvoltage to be amplified is applied through a current limiting resistance38 to the control grid 33 of an ampler tube 48 (RCA type GAC'?) operatedthrough the power supply I2.

The cathode 4I of the said tube 48 is connected through conductor 42 tothe cathode of oscillator tube I8, the screen grid 43 to the positivetermina1 44 of the power supply I2 and the suppressor grid element 45thereof through conductor 45 to the negative terminal 2| of the powersupply i2. The circuit herein described is adapted'to operate a fourcoin registering machine and to this end four relays 41, 48, 49 and 55are provided and connected in series through conductor I to the anode 52of tube 45 and through conductor 53 to the positive terminal 22.

vCurrent will circulate from the power supply through the windings ofthe said relays and through the tube 45 to return to the power supplyI2. The signal voltage or variable bias developed across resistance 3lis applied to the control grid 39 of the tube 45 in a polarity sensesuch that the grid 39 becomes more negative with respect to the cathode4I with increasing current through diode thereby reducing the current owthrough the said tube 45 and the said relays.

Under conditions such as when there is no coin in the eld of the coil32, the tube will conduct a maximum ,amount of current through theanode, cathode circuit, the said relays to energize to close theircontacts 54, 55; 55, 51; 58, 59; and 55, 5I; respectively, the contacts52, 63, 54, and 55, respectively, of the said relays being opened. rThesaid relays are identical and are made to operate at different values ofcurrent by means of different values of resistors 61, 58 and 59 whichare connected in parallel wtih the coils of the said relays so as todivide the relay current between the said resistors and the coils of thesaid relays in inverse proportion to their resistances so that thecurrent flow through the coils of the relays is only sucient to hold thesame energized in accordance to a predetermined current iiow in therelay circuit 55. The

pairs of normally closed contacts 54, 55; 55, 51; 58, 53; and 55, 5i;respectively, are connected in series from the negative side of a sourceof potential 15 through conductor 1I to a junction point 12, thusnormally short-circuiting the winding of relay 85 and providing aninterlocking arrangement for these pairs of contacts of the said relays.

Each relay operates a separate solenoid for actuating a particularcounter for each diierent coin to be registered. In the presentinstance, dimes, cents, nickels, and quarters are to be registered andsolenoids 13, 14, 15, and 16 and which may `be referred to as the dime,cent,

nickel and quarter solenoid respectively, are provided for actuating thesaid counters (not shown) and a solenoid 11 is provided for operatingand indexing the pins 31 previously referred to. Each solenoid 13, 14,15, and 15 has one side of its winding connected to the normally openedcontact of its relay and the other side of its winding connected inseries through a common conductor 18 to one side of the winding of theindex solenoid, the other side of which index solenoid winding isconnected through the normally opened contacts 19 of a delay relay 88 tothe positive of the potential 15. The winding of relay 88, shunted by aseries connected resistance 8l and capacitor 82, is connected acrosssource 1I) in series with resistor 83. The Winding of relay is normallyshorted by the closed contacts 54, 55, 55, 51, 58, 53, 58 and 5I. Theresistor 8l and capacitor 82 form a time circuit to delay the energizingof the relay 80.

As previously stated, the resistance 51, 58 and 59 are of differentvalue, and the resistance 51 is of a value such that only suilicientcurrent will flow through the winding of the relay 41 to hold itenergized, the remainder of the relay circuit current being by-passedthrough the resistance 51. The presence of a dime in position in themagnetic field of the coil 32 will reduce, as above pointed out, thecurrent iiow through the relay circuit 55 in an amount less than thatrequired for holding the relay 41 energized, therefore releasing theclosed contacts 54, 55 of relay 41 to move to open position and closingthe contacts 54, 52 to close one side of the circuit of dime solenoid13. The reduction in relay current in the relay circuit by the presenceof a dime in the magnetic field of the coil 32 is not suicient to allowdeenergizing of the coils of relays 48, 49, and 58. The opening ofcontacts 54 and 55 will remove the short circuit across the windings ofrelay 85 which will now start to energize through resistance 83,capacitor 82, and resistance 8|, the values of which are chosen so as toprovide a definite time delay for the complete energizing of relay 58,to close its normally opened contacts 19 to complete the circuit of thedime solenoid 13 to energize the same to actuate its counter and to alsoclose the circuit of the solenoid 11 to operate to index or move thepins 31 to release the dime to move out of the eld of the coil 32. Withthe coin released the entire circuit will return to normal.

With a cent in position in the field of the coil 32, the flow of relaycurrent will be reduced sufficiently to permit both relay 41 and 48 torelease the closed contacts 54, 55, and 55 and 51 and close contacts 54,52 and 55, 53 and thereby connecting the negative side of the potential10 to the winding of solenoid 14, and opening the circuit of thesolenoid13 at the contact 51 prior to the energizing of relay 85 to closecontact 19 to complete closing of the circuits of solenoids 14 and 11 toregister the cent and index the pins 31.

The registration of a nickel and quarter is performed in the same manneras above described. fn registering a nickel the dirne solenoid circuitis opened at contact 51, and the cent solenoid circuit at contact 59. Inregistering a quarter, the nickel solenoid circuit is opened at contact5 I.

While a feedback type oscillator I5, I I are shown by way ofexampleonly, it is to be understood that these may be replaced by anyconventional oscillator circuit and further thatA amplier tube 45 may bereplaced by any type, so long as it contains a control grid. Additionalmodications as the replacement of the time delay relay by mechanicaltypes may well suggest themselves to those skilled in the art and arenot to be limited except as dened in the appended claims.

I claim:

l. In a sorting device, two oscillators each having an output circuit, arectifying device connected to said output circuits, a load resistorconnected to the output of said rectifying device, means connected tosaid resistor responsive to changes in current therein, said meanscomprising a plurality of pilot relays each being respon-v sive to adifferent current value, each of said pilot relays controlling a secondrelay, the contacts of said pilot relays being in circuit with a sourceof potential and the windings of said second relays and each comprisingone set of make-break contacts serially arranged so that only one ofsaid second relays is energized irrespective of the number of energizedpilot relays and a time delay relay also in circuit with the windings ofsaid second relays to delay the action of said second relays until thepilot relays have assumed a static condition.

2. In a fare registering machine, two oscillators each having an outputcoil inductively coupled to the oscillating circuit, a rectifyingdevice, a load resistor, said output coils being connected in serieswith said rectifying device and said load resistor, a vacuum tube havingatleast an anode, grid and cathode, said load resistor being connectedin the grid-cathode circuit of said tube, a source of potential havingits positive terminal connected to said anode and its negative terminalto said cathode, a plurality of relays having their windings connectedin the space current path of said tube, and each being responsive to adiierent current value, each of said relays controlling a second relay,the contacts of said first relays being in circuit with a source ofpotential and the windings of said second relays, each of said firstrelays comprising one set of make-break contacts serially arranged sothat only one of said second relays is energized irrespective of thenumber of energized pilot relays, and a time delay relay` also incircuit with the windings of said second relays to delay their actionuntil the pilot relays have assumed a static c ondition.

3. In a fare registering machine, two oscillators each having an outputcoil inductively coupled to the oscillating circuit, a rectifyingdevice, a load resistor, said output coils being connected in serieswith said rectifying device and said load resistor, a vacuum tube havingat least an anode, grid and cathode, said load resistor being connectedin the grid-cathode circuit of said tube, a source of potential havingits positive terminal coupled to said anode and its negative terminal tosaid cathode, a plurality of relays having their windings connected inthe space current path of said tube, a plurality of shunt resistorsconnected across said relay windings so that the effective resistance ofeach relay winding is of a different value, the contacts or" said relaysconnected to operate a plurality of counter solenoids, means connectedin the solenoid circuit to delay application of voltage thereto apredetermined time to allow said relays to reach a stable condition, andmeans for varying the bias on the grid of said tube whereby each of saidrelays will be operated successively as the bias changes.

ALEXANDER M. GORDON.

REFERENCES CITED The following references are of record in the le ofthis patent:

UNITED STATES PATENTS Number Name Date 1,649,828 Hund Nov. 22, 19272,017,894 Cady Oct. 22, 1935 2,086,892 Barton July 13, 1937 2,096,881Butler Oct. 28, 1937 2,123,470 Lamb July 12, 1938 2,295,894 Dewan Sept.15, 1942 2,512,879 Rcggenstein June 27, 1950 2,525,016 Borell Oct. 10,1950 FOREIGN PATENTS Number Country Date 319,184 Germany Mar. 5, 1920OTHER REFERENCES Electronic Industries, February 1946, pages 94,195, 96and 132.

